Liquid tank



Patented Nov. 15, 1938 UNITED STATES PATENT OFFICE LIQUIDV TANK Application pril 16, `1937, Serial N0. 137265 3 Claims.y

This invention' relates' to improvements in tank constructions'such as water storage tanks, swimming tanks or the like, and refers specifically to aconstruction which, in spite of soil subsidence or otherl cracking agencies Will not be caused to deteriorate through leakage. Y

Heretofore much attention has been given to rendering the walls of concrete or masonry'tanks waterproof. It has'been' proposed' to make the Hl masonry waterproof by incorporating waterproof materials inY the cement itself'. Also the walls have heretofore been covered by many kindsof Waterproofing bitumastics or by interposing betweenthe Walls paper'or felt impregnated with waterproofing material but as the structure ages and settling takes place, due to soil subsidence or" some'otherucause, the masonry or concrete Walls'Will eventually crack and with the cracking of the walls the continuity of the waterproofing is also .broken thereby allowing leakage to take place from the tank. Of course, this is a serious feature when the tank is enclosed in a building inasmuch as it may prove detrimental to the foundation of the building itself, and even when the tank is not contained in a building the leakage may be detrimental to the foundation of the tank. Therefore, it is seen that the chief difl'lculty of the types of waterproong which have been used heretofore is their inability to maintain a continuity of the waterproofing i'llm. When bitumastics are used, many of them become hard and brittle when cold and when heated become so soft that they flow o-ut of position. When Afelt or paper are used there is not sufficient elongation to take care of the movement which will take place between the inner and outer walls if there is any soil subsidence.

As a feature of my invention I have found that rubber forms an ideal material for a waterproofing layer of this type. It is soft and yielding enough to follow any irregular contours. It can also be elongated to permit relative movement of the inner and outer Walls. It is so little affected 4by heat that it maintains practically the same consistency under any conditions of storage. It will elongate Without tearing or rupturing and thus fullls all the requirements of an ideal Waterproofing inner layer.

My invention, briefly described, resides in a tank construction comprising an outer masonry or concrete defining wall and a layer of rubber or other tenacious resilient Waterproofing material interposed between said inner and outer walls, whereby cracking of either the inner or (CL' 'I2-14) outer wall or both will not resultin leakage from the tank.

The object and advantages of myinvention will be apparent from the accompanying drawing and' following detailedY description;

In the drawing, Fig. l is afragmentary', perspective View of a portion` of a tank constructed in accordance with my invention.

Fig. 2 is a sectional View takencnl line 2-2 of Fig. 1.

Referring in detail to therdravving, I indicates a concreteside wall which' maybe constructed of poured-i'n-place concretev and may be formed integra-l with the bottom 2, opposite sidewall1 and endE walls (not shown). Adjacent the top of the wall I the thickness thereof may be restricted, as indicated at 3 in Fig. 2 to forman offset or` shoulder 4.` v 1 f To the innerk face of substantially the entirearea of the`v wall l,bcttom` 2, opposite wallan'd endI wal'ls,a` layer 5` of rubber is disposed. The' layer 5 is resilient and in effect provides a waterof the side and end Walls the rubber may becarried over the shoulder 4. f

Aninner wall 6 is formed of the poured-inplace concrete exteriorly of the rubber layer 5 and similarly a bottom 1 is disposed on top of the rubber layer at the bottom of the tank.` Similar to the outer structure, the inner structure is preferably integrally formed whereby the rubber layer 5 is interposed between two integral pouredin-place concrete structures defining the tank. The wall 6 as well as the opposite wall and end walls of the structure (not shown) and upper marginal edges are offset, as shown at 8 in Fig. 2, adjacent shoulder 4.

'Iile 9 may be laid adjacent the inner face of the inner concrete structure and covers the entire surface of said structure, the tile following the contour of the structure at 8 to provide the shoulder I0 which extends entirely around the marginal edge of the tank.

The above described structure is directed particularly to a tank which may be used for swimming purposes. It is to be understood, of course, that my invention is equally applicable to other types of tanks such as water storage tanks or liquid vats wherein the walls are constructed of masonry, brick or concrete.

Acid vats and pickling tanks have heretofore been constructed wherein a rubber layer has been used between the outer walls of the tank and the inner acid resisting linings. In such tanks, however, the outer walls are usually constructed of metal and the prime function of the rubber layer or liner is to prevent contact of the acid with the tank walls. In addition, it has heretofore been proposed to interpose waterproofing bitumastic layers between masonry or brick walls of water storage or swimming tanks. As has been hereinbefore pointed out, such bitumastics have decided disadvantages, for instance, they may become hard and brittle through time and lose all resilient characteristics. Moreover, when used in conjunction with felt or paper they do not possess to the desired degree the characteristic of elongation. In using a resilient rubber layer between masonry walls I nd that the layer performs a function other than its function when used in pickling tanks or acid vats.

One characteristic of masonry, brick or concrete is that it is extremely weak in tension and, consequently, when aiTected by soil subsidence it readily cracks. 'Ihis action, of course, cannot take place with regard to the metal layer of a pickling tank or acid vat and, consequently, the rubber layers used therein are not constructed to follow the irregular contours which may result from the cracking of the wall. When my rubber layer is used between masonry walls, however, the layer must function to accommodate itself to various displacements of the inner and outer walls when cracking occurs so that the continuity of the iilm may be preserved. Of course, when Waterproofing bitumastic or saturated felts or papers are used and cracking of the masonry or concrete walls occur, the so-called waterproofing layer cracks and is severed when the Walls crack.

It is to be understood, of course, that although my invention is particularly directed to the provision of a resilient rubber layer, other materials 'possessing similar characteristics may be used.

The/characteristics of most importance are those of resilience or flexibility. The layer, of course, must be waterproof and capable of being elongated without rupturing, as when the conning walls crack or local portions thereof are relatively displaced.

By the expression relatively brittle material" as used in the claims is meant a wall structure constructed of a material low in tensile strength such as concrete, masonry, brick, tile or the like, as opposed to a material such as metal which will not readily crack when exposed to unbalanced stresses.

I claim as my invention:

1. A liquid tank which comprises an outer concrete structure and an inner concrete structure, said structures defining said tank, a layer of waterproof resilient material capable of elongation and deformation without rupture comprising sheet rubber interposed throughout b etween the inner and outer concrete structures.

2. A liquid tank which comprises an outer structure of relatively brittle material and an inner structure of relatively brittle material, said structures dening said tank, and a. layer of exible sheet rubber interposed throughout between the inner and outer structures and adapted to maintain a liquid seal for said tank upon fracture of said structures and deformation of the contour of said tank.

3. A liquid tank which comprises an outer structure of relatively brittle fracturable material and an inner structure of relatively brittle fracturable material, said structures dening said tank, and a continuous layer of iiexible sheet rubber interposed throughout between the inner and outer structures whereby a liquid seal will be maintained for said tank upon fracture of sai-d material.

CHARLES PATRICK MCHUGH. 

